Distilling process



rnrrz return, or

Paras-tr caries,

VIENNA, acs'raral nrsrrrrme rrtocnss.

riomrawing. Application filed Mayl,

To all whom itmay concern:

Be it known that I, Fnrrz PoLLAK, a citizen of the Czecho-Slovak Republic, and residing at Vienna, Austria, have invented certain new and useful Improvements in a Distilling Process (for which I have filed an application in Austria Nov. 8, 1918, and in Germany Jan. 21, 1919), of which the following is a specification. y

\ This invention relates to the art of distilling volatile'substances, and in particular a volatile liquid wherein volatile substances are dissolved, and it has for its purpose so to modify ,certain steps of the process as to afford possibility for obtaining a distillate any part of which containsthe original constituents in the same ratio.

According to the usual method of distilling, the heat required for the liquid under treatment is supplied by heating the outer shell of the vessel or by heating devices in troduced into the liquid, in such a manner that heating ofthe substance to be distilled far beyond its vaporizing temperature is avoidedf At difierence with this process, the material under treatment is, according to the process forming the subject-matter of the invention, heated in very small particles to such, a high 'ten peraturrthat'every particle is vaporized by an explosion-like action. The escaping vapors are collected and condensed in the usual way. When distilllng a mixture of volatile matters, the temperature to which the material under treatment is to be heated, must be higher than the vaporizing temperature of the least volatile constituent. For carrying the process into practice, one may, for instance cause the mixture to fall in drops upon' a surface heated beyond vaporizing temperature of the least volatile constituent. liquid forms spherical bodies suspended over a portion of vapor and vaporizing with ex-' plosion-like rapidity. In consequence of this rapid, simultaneous vaporization of all constituents of the mixture, the distillate contains in all its portions the components of the mixture under treatment in the same ratio as they originally therein existed. Even differences of '100'C. between the vaporizing points of the constituents do not play i in this 'case any considerablea part. Consequently, the problem occasi'onally presenting itself to the chemist,'thu s to distill a.

Thereat the Specification of Letters Patent. Pat g t d J l 11 19,22;

1920. Serial No. 378,244.

v mixture of volatile substances, for instance a liquid wherein volatile substances are dissolved, that each portion of the distillate contains the same components, no matter the vaporizing points of the single components of the mixture, may be solved in a simple manner. The escaping vapors may be fractioned by gradual refrigeration.

Such fractional condensation is well lrnown to the art, and my invention has nothmg to do with the specific operating conditions of this step of the process.

It depends on the nature of the liquid to be heated and on the purpose of the distillation to what temperature above the vaporizing temperature of thesubstancelto be distilled'or of the least volatile component of a mixture, the heating surface is to be brought. Whose vaporizing point lies considerably below 250 C., a metal vessel is in general used, which is at most, heated to dark redheat. With bodies whose vaporizing point is nearer to 400 C. and whose inflammation temperature is high one heats to advantage to bright red-heat. hen a metal alloy is to be distilled, one is in mostcases obliged to use yet higher temperatures. For reasons ofeconomy, it is advantageous exactly to "adjust, beforehand, the temperature of the heated surface in each special case. Instead of applyingthe substance to be distilled to suitably heated surfacesfilt may also be in small portions introduced into hollow Spaces of suitable temperature. The heating surface or the sides of the heated hollow spaces may be formed of suitable minerals, metal oxids or metals salts. Divers materials suit this purpose, for instance noble metals, copper, iron, asbestos, graphite, silica, silicates, magnesia, clay etc. Theclioice of the material depends on the conditions under which working is carried 0I l.

The supply of heat may electric resistance heating or by other sources of calorie, such as gas, coke or coal furnaces. The distillation act may ,take place at the ordinary'pressure of air, or at reduced or increased pressure. In order to' For the distillation of bodies be efi ected by could not be obtained at all. Thus, it was densation to a temperature ofabout 70 0., not possible hitherto to distill the aqueous and" by only from this temperature downformaldehyde solution of the trade, which ward as far as'the normal temperature, percontains methyl alcohol. As is well known, mitting the refrigeration to actin the nor- 5 methyl alcohol is oxydized by passing it mal rapid way. 70 over red hot metals. Thereupon, apart of In carrying the process into pract1c/e,-a the vapor of methyl alcohol always escapes condensed liquid free of methyl alcohol may its burning to formaldehyde. Such, solube immediately obtained by delivering the tions contain furthermore dissolved gaseous escaping vapors from the methyl alcohol formaldehyde, formaldehyde-hydrates,polythrough oxydation, before their condens- 75 oxymethylenes, etc. When such a mixture ation. This can be done, for instance, by

is heated in the manner hitherto in-use, first causing the vapors to pass over an incandesdistills over a mixture of methyl alcohol, cent copper spiral. formaldehyde and steam; thereafter ensues What I claim is:

a weak aqueous solution of formaldehyde 1.- The described distilling process which 80 whose boiling point is near to 99 to 102 consists in heating a mixture of substances C. The residue consists of polymeric forto be distilled in small portions to a suitmaldehyde which, after the complete volatiable temperature to vaporize all constituents lization of the solvent, forms a white of different vaporization points rapidly and amorpheous powder. This vproduct does not simultaneously, and collecting and condens- 85 melt on being further heated but .it subing the escaping vapors containing in each limes a little below 150 C., when it decomportion the components of the mixture unposes to gaseous formaldehyde. The gaseder treatment in the same ratio as they ous formaldehyde repolymerizes however originally therein existed. I o

immediately on cooling. The nature of the 2. The described distilling process which 90 sublimate is not always uniform but deconsists in heating a mixture of substances pends on the conditions of condensation. of different vaporization points to be dis- Anyhow, there can be no quest-ion of a regutilled to a temperature higher than the lar suitability for distillation of the original vaporization: point of the least volatile con-- mixture. For this reason, one was'obliged stituent to vaporize all constituents of the 95' to start from paraformaldehyde for obtain- 'mixture rapidly and simultaneously and in ing aqueous solutions of formaldehyde free collecting and condensing the escaping vapfrom methly alcohol. The paraformalde-v ors contained in each portion the 'comhyde was gasified and the repolymerization ponents of the mixture under treatment in of the gas was prevented by blowing it, with the same ratio as they originally-therein ex-. 100

the aid of a nitrogen current, into a reisted. frigerated receiver, in which it was either I 3. The described distilling process which liquified at a temperature of 20 C., or consists in heating a volatile liquid wherein caught in water. As thereat continuous volatile substances are dissolved .in small 40 cloggings of the pipes took place, because; 0 to a temperature exceedingtheva- 105 at any sensibly cooler point, repoly size porization point-of the least volatile conparaformaldehyd precipitated this process stituent and in then-condensing the escapif' 4 is also absolutely gnfit frf the techanical vapors whereby a distillate is obtained, eacf production of/so'lutions of formaldehyde portion of which contains the same componfree of methly alcohol. On the contrary, 'ents, no matter what vaporization points the 11Q when aqueous solutions of formaldehyde of individual constituents of the mixture under this kind are caused to fall in small drops treatment may have. upon surfaces, which are heated beyond the 4. The described distilling process which vaporization temperature of the least vola-' consists in heating. a mixture of substances tile of the polymeric 'formaldehydes conof different vaporization points to be distilled tained in the .mixture, for instance of the to a-temperature higher than the vaporizaparaformaldehyde, and when the evolved tion point of the least volatile constituent to vapors are collected for condensation, a vaporize all constituents of the mixture rapsimultaneous vaporization of all volatile idly and simultaneously, and in fractionally 55 constituents of the mixture is attained. condensing-the escaping, vapors by gradual However, when the vapors are too rapidly refrigeration.

cooled, it may arrive that a weak solution of 5. The described distilling process. which formaldehyde is collected by the receiver, consists in causing a mixture of substances of while at the same time a smoke-like vapor different vaporization points to be distilled 60 escapes unc'ondensed. It seems that this to be applied in very smallp'aiticles to sur fact is to be ascribed to the formation of faces which are heated to a temperature crystalline polyoxmethylenes, which are higher.than the vaporization point of the little soluble in water. This drawback may least volatileconstituent' of the mixture, and certainly be avoided by very slowly coolin condensing the escaping vapors to obtain 65 ing down the vapors passing away for con-- a distillate containing in each portion the components of the mixture under treatment in the same ratio as they originally therein existed.

' 6. The described process of distilling aqueous solutions of formaldehyde, containingformaldehyde-hydrates, polymers of the formaldehyde and methyl alcohol, the said process consisting in causing the solution to drop in small particles upon surfaces heated beyond the vaporization temperature of the least volatile of the polymeric formalde-f hydes, and in collecting and condensing the escaping vapors.

7. The. described process of distilling aqueous solutions of formaldehyde, containing formaldehyde-hydrates, polymers'of the formaldehyde and methyl alcohol, the said process consisting in causing the solution to drop in very small particles upon surfaces heated beyond the va orization temperature of the least volatile o the polymeric formaldehydes, in collecting the escaping vapors and-for the purpose of condensation-in first cooling them very slowly down'to 7 0 (1, and afterwards'refrigerating them in the usual manner.

8. The "described process of, distilling aqueous solutions of formaldehyde, containing formaldehyde hydrates, polymers of the formaldehyde and methyl alcohol, the said process consisting in causing the solution to drop in' very small particles upon surfaces heated beyond the vaporization temperature of the least volatile polymeric formaldee.

hydes, leading the escaping vapors over an incandescent copper spiral, and finally condensing them.

aqueous solutions. of formaldehyde, containing formaldehyde hydrates, po ymers of the formaldehyde, and methyl alcohol, the said process consisting in causing the'solution in small particles to drop. upon surfacesheated beyond the vaporizing temperature'of the least volatile of the polymeric formaldehydes, leading the escaping vapors over an incandescent copper spiral, and in finallyfor the purpose of condensation-first cooling the vapors very slowly down to 70 C. and afterwards refrigerating them in. the usual way. n In, testimony whereof I have afixed my signature.

FRITZ roman.

10. The described process of distilling 

